Hydrogeologic Controls on the Groundwater Interactions with an Acidic Lake in Karst Terrain, Lake Barco, Florida

Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain.

[1]  A. Swancar,et al.  Influence of evaporation, ground water, and uncertainty in the hydrologic budget of Lake Lucerne, a seepage lake in Polk County, Florida , 1997 .

[2]  R. Ragan.  An experimental investigation of partial area contribution. , 1968 .

[3]  A. Swancar,et al.  Methods, instrumentation, and preliminary evaluation of data for the hydrologic budget assessment of Lake Lucerne, Polk County, Florida , 1991 .

[4]  Arlen W. Harbaugh,et al.  A Computer Program for Calculating Subregional Water Budgets Using Results from the U.S. Geological Survey Modular Three-dimensional Finite-difference Ground-water Flow Model , 1990 .

[5]  T. Steenhuis,et al.  Measurement of groundwater recharge on eastern Long Island , 1985 .

[6]  Terrie M. Lee,et al.  Comparison of energy-budget evaporation losses from two morphometrically different Florida seepage lakes , 1994 .

[7]  T. C. Winter.  Numerical simulation analysis of the interaction of lakes and ground water , 1976 .

[8]  B. Beck,et al.  Sinkholes : their geology, engineering, and environmental impact : proceedings of the First Multidisciplinary Conference on Sinkholes, Orlando, Florida, 15-17 October 1984 , 1984 .

[9]  A. Hine,et al.  High-Resolution Seismic Expression of Karst Evolution within the Upper Floridan Aquifer System: Crooked Lake, Polk County, Florida , 1994 .

[11]  J. Eilers,et al.  Alkalinity regulation in softwater Florida lakes , 1988 .

[12]  L. A. Sacks,et al.  Hydrogeologic setting and preliminary data analysis for the hydrologic-budget assessment of Lake Barco, an acidic seepage lake in Putnam County, Florida , 1992 .

[13]  T. C. Winter.  The interaction of lakes with variably saturated porous media , 1983 .

[14]  W. A. White,et al.  The geomorphology of the Florida Peninsula , 1970 .

[15]  Thomas C. Winter,et al.  UNCERTAINTIES IN ESTIMATING THE WATER BALANCE OF LAKES , 1981 .

[16]  T. C. Winter,et al.  Effect of anisotropy and groundwater system geometry on seepage through lakebeds: 2. Numerical simulation analysis , 1984 .

[17]  D. Canfield,et al.  Regional Geology and the Chemical and Trophic State Characteristics of Florida Lakes , 1988 .

[18]  D. Jorgensen,et al.  Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 1. Problems and concepts , 1989 .

[19]  J. Eilers,et al.  Chemical and physical characteristics of lakes in the northeastern United States. , 1988, Environmental science & technology.

[20]  David E. Prudic,et al.  Documentation of a computer program to simulate aquifer-system compaction using the modular finite d , 1988 .

[21]  David W. Pollock,et al.  Documentation of computer programs to compute and display pathlines using results from the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model , 1989 .

[22]  L. N. Plummer,et al.  Chemical Evolution of Groundwater Near a Sinkhole Lake, Northern Florida: 1. Flow Patterns, Age of Groundwater, and Influence of Lake Water Leakage , 1995 .

[23]  A. Sturrock.  INSTRUMENTATION FOR MEASURING LAKE AND RESERVOIR EVAPORATION BY THE ENERGY-BUDGET AND MASS-TRANSFER METHODS , 1985 .

[24]  R. Stauffer.  Effects of citrus agriculture on ridge lakes in Central Florida , 1991 .

[25]  W. J. Andrews,et al.  Preliminary Analysis of the Hydrologic and Geochemical Controls on Acid‐Neutralizing Capacity in Two Acidic Seepage Lakes in Florida , 1991 .

[26]  Arlen W. Harbaugh,et al.  A modular three-dimensional finite-difference ground-water flow model , 1984 .

[27]  J. Labaugh.  Uncertainty in Phosphorus Retention, Williams Fork Reservoir, Colorado , 1985 .